In a modern-day society, increasing use is being made of railway vehicles to perform infrastructural tasks in the area of passenger transport. Particularly stringent fire protection requirements have, of course, to be laid down for the relevant passenger trains. Hitherto, this has been reflected in stringent requirements for the material and equipment used in the trains. Corresponding standards and other requirements relating to the design of trains and to their construction and to the materials and equipment selected constitute not inconsiderable restrictions on the makers and operators of trains when new projects are being carried out. When vehicles belonging to old rolling stock are being brought up to a fit state, it is only with difficulty, or not at all, that the conditions imposed by the authorities can be met.
It can be expected that, in the next few years too, rail systems are increasingly going to be laid wholly or partly underground. Because of the particular problems that fire protection poses in tunnels, there will therefore continue to be a steady rise in the requirements that railway vehicles have to meet.
Added to this is the fact that it is only the way in which the rolling stock itself behaves in fires that can be influenced by the design of the vehicles and by the materials and equipment selected. There is on the other hand no way in which the fire loads such as clothing and luggage which the passengers take on with them can be influenced. Even the taking on of incendiary materials by arsonists is almost impossible to prevent.
The fire-fighting systems for the spaces occupied by passengers which have hitherto been installed in railway vehicles, which has only happened anyway in exceptional cases, have mostly been of the “open system” or “wet system” types.
In the first case, it is necessary in addition for a fire detection and alarm system to be installed which will detect fires and will then give the fire-fighting system an activating signal for the area affected. To keep down the system costs in terms of valves controlling the area, the particular devices for dispensing extinguishing agent are not activated individually but, regularly, in groups. The result of this is that the amount of extinguishing agent used is greater than it would be in the case of selective individual activation. This in turn means that the supply of extinguishing agent, and hence the weight which has to be carried, turns out to be higher.
In the wet system, the devices for dispensing extinguishing agent are activated by thermal triggering elements in the individual devices. This gives individual activation. However, the entire pipe network out as far as the devices for dispensing the extinguishing agent has to be pre-filled with extinguishing agent in this case. This is not without its problems, because in certain circumstances the vibration typical of railway vehicles might causes leaks of greater or lesser severity in the network of piping, allowing the extinguishing agent to escape, as a result of which not inconsiderable damage might be done even though the amounts were very small.
The above-mentioned measures for improving fire protection are what are called passive measures. As described, they are a considerable restriction on makers and operators. There are significant imposed tasks which cannot be performed at all by passive fire protection measures.